Hands Solo has just about covered it Pandora, don't envy you though.
Always difficult dealing with such individuals, they are determined to be noticed as the one with the lowest numbers when it comes to fuel uplift, believing themselves to be the most economic. It is a fallacy of course, they are the ones most likely to have to divert and then, in the charter world anyway, you could have wiped out the profit from the next six flights.
From a CRM point of view he doesn't seem to have bothered himself with it, he should have discussed it and justified his position to you but going below SWORD is foolhardy to say the least.
If it happens again remind him of these two previous events and follow Hands Solos's advice above.
There is also CHIRP. Best of luck.